docs: def dict_to_ddb(item):
      # type: (Dict[str, Any]) -> Dict[str, Any]
      # TODO: narrow these types down
      """Converts a native Python dictionary to a raw DynamoDB item.
  
      :param dict item: Native item
      :returns: DynamoDB item
      :rtype: dict
      """
      serializer = TypeSerializer()
      return {key: serializer.serialize(value) for key, value in item.items()}